High-level sounds, and particularly the recurrence thereof, are known to cause hearing impairment, and in extreme cases, the loss of hearing. In order to avoid the hearing impairments, numerous types of hearing protectors for noise reduction has been proposed to be used in different fields and uses such as military, industrial applications and music.
One of the most common hearing protectors is a foam earplug. Foam earplugs are rolled-down and inserted into the ear canal. When the rolling pressure is interrupted, the plug expands to fit the inner morphology of the ear. One of the limitations of foam earplugs is that they are intended to filter a broad range of sound frequencies. If the wearer needs protection for a specific range of sound frequencies—or when the user needs a less attenuating product in order to hear voice or warning signals—he will have to completely remove the earplugs and take a new pair of plugs made of different material, or filter with passive or active acoustical means. This procedure represents a disadvantage, since it renders the user unprotected during the transition.
There is in the market an ear protective device that can be adjusted according to two different frequency response operating modes. This device has the possibility to switch between two different levels of sound attenuation. However, the device requires that it be removed from the ear before changing from one operating mode to the other because of the rotating knob that rotates within a plane substantially parallel to the axis of the entrance of the ear canal (or about an axis substantially perpendicular to a plane of the outer ear). Again, this procedure renders the user unprotected during the transition.
Accordingly, there is a need for an improved in-ear device that enables the wearer to switch between different levels of attenuation protection, without compromising his auditory protection.